Breakdown Characteristics of Eco-Friendly Gas C₅F₁₀O/CO₂ Under Switching Impulse in Nonuniform Electric Field

Regulation mechanism of porous structures on flashover performances: combined effect of hindering collision ionization and corona stabilization

“…Therefore, we believe that the above phenomena are not only caused by the inhibition effect of porous materials on collision ionization, but also by the corona stabilization effect at the three junction points. The corona stabilization effect has been illustrated in [25][26][27], and will be discussed in the following sections. The inhibition effect on collision ionization and the corona stabilization effect of porous structures are examined by the experiments in the following sections, and the specific mechanism will be discussed in section 3.3.…”

“…It has been pointed out that the corona stabilization effect plays significant roles in the discharge behaviors of electronegative gas [26,27]. A stabilized corona discharge volume can be formed near the needle electrode, which reduces the electric field strength at the front of the tip, and forces the subsequent streamer channels bypass this region.…”

“…The flashover strength at gas pressure of 0.10-0.3 MPa is significantly improved due to the combined effect of hindering the collision ionization and corona stabilization. As the gas pressure increases, the volume of the corona discharge decreases and the corona stabilization effect is weakened [26,27], which reduces the flashover strength at 0.4 MPa. Moreover, as the pore diameter decreases, the corona discharge volume also decreases and weakens the corona stabilization effect, thus the deflected angle decreases.…”

“…In addition, the hindering effect plays more significant role in improving flashover strength for membranes with small pore diameters. The corona stabilization effect has been employed to explain the hump curve of breakdown voltage with gas pressure and PD behaviors in electronegative gas [25][26][27]. A positive needle-plane electrode structure was usually used in these researches, and the corona stabilization effect was described in slightly different ways in these literatures.…”

“…The collision ionization of gas molecules is inhibited by the obstruction effect of high-density solid structures on electrons [23,24]. At the same time, due to the influence of pores, porous materials are prone to form the corona stabilization effect [25][26][27], which weakens the electric field strength at the triple junction point, thus increasing the flashover voltage. This paper aims to reveal the influencing mechanism of porous structures on flashover strength and provides a reference for the improvement of surface insulation performances.…”